This invention relates generally to crop residue choppers and spreaders for agricultural combines, and, more particularly, to a vertical chopper and spreader that provides better residue flow therethrough compared to known horizontal choppers and spreaders and better and greater sideward spreading and dispersal of the residue over a field from which the crop was harvested.
Crop residue choppers and spreaders for agricultural combines are well known. Reference in this regard Hirsch U.S. Pat. No. 6,070,816 issued Jun. 6, 2000 to Deere and Company, which discloses a straw chopper utilizing a pair of rotors rotatable about respective vertical axes and outfitted with a number of circumferentially spaced vertically arrayed impeller blades which intermesh with vertical arrays of shear bars in vertical spaces in a housing containing the rotors, for chopping crop residue which enters the spaces through sideward openings in the housing. An observed shortcoming of choppers such as this, however, is that the rotors are enclosed at the top, which prevents crop residue flow thereto from that direction so as to necessitates placement of the chopper at a relatively high location to allow for the infeeding of the crop residue thereto from the side. However, even at the higher location, straw separated from the grain by the threshing mechanism of the combine at a high location and blown or otherwise conveyed or fed to the chopper must follow a xe2x80x9cdog legxe2x80x9d or similar path including one or more sharp bends to enter the chopper. As another observed shortcoming, due to the horizontal rotation of the rotors about vertical axes, the range of crop residue dispersal over a field can be limited, as the trajectory of the crop residue when propelled from the chopper is basically only horizontally or downwardly, not upwardly which would allow for a longer trajectory for a given motive force. Still further, a disadvantage of utilizing impeller blades on a rotor of a chopper cooperable with shear bars on a housing containing the rotor for achieving a cutting effect, is that it is not easy to convert the chopper to solely operation as a spreader, as is desirable for some harvesting applications.
Thus, what is sought is a rotary chopper for an agricultural combine which overcomes the shortcomings and disadvantages discussed above.
According to the invention a crop residue chopper and spreader for an agricultural combine which overcomes many of the shortcoming and disadvantages discussed above is disclosed. The chopper and spreader includes a disk mounted for rotation in a predetermined rotational direction about an axis oriented horizontally or at a small acute angle to horizontal, the disk including at least one radially outwardly extending impeller having a radial outermost periphery. The chopper and spreader includes a housing at least partially containing the disk and including an upwardly facing inlet opening located generally above the disk for receiving a flow of crop residue from a threshing mechanism of the combine, and a radially facing discharge opening located generally below the disk for discharging the flow of crop residue. The chopper and spreader additionally includes cutting elements mounted on the housing and on the radially outermost periphery of the at least one impeller cooperable for cutting the crop residue when passing through the housing from the inlet opening to the discharge opening.
The cutting elements can include knives on the radial outermost periphery of the at least one impeller cooperatively receivable in slots in the housing as the disk is rotated, or knives at fixed locations on or in the housing positioned to pass through slots in the radial outer periphery of the at least one impeller when rotated.
Additionally, one or more flow guides are preferably disposed adjacent to the discharge opening for guiding the flow of crop residue discharged from the chopper and spreader radially outwardly and sidewardly from the combine for dispersal over a field from which the crop was just harvested. One or more flow deflectors can also optionally be disposed downstream in the discharged crop residue flow for damping or further guiding the flow.